Light processing systems often involve directing light towards a display such that an image is produced. One way of effecting such an image is through the use of digital micro-mirror devices (DMD) available from Texas Instruments. In general, light is directed through a lens array to a DMD array having numerous micro-mirrors. Each lens element in the lens array magnifies light from a light source to cover the active area of the DMD. Each micro-mirror is selectively controlled to reflect the light towards a particular portion of a display, such as a pixel. The angle of a micro-mirror can be changed to switch a pixel to an “on” or “off” state. The micro-mirrors can maintain their “on” or “off” state for controlled display times.
The DMD is often not perpendicular to the axis of the lens array that directs light to it. The DMD is generally at an angle from the axis of the lens array so that light from the lens array can be reflected off of the active area of the DMD towards a target such as a screen or display. This angle between the DMD and the axis of the lens array causes a distortion of the shape of the light on the plane of the DMD. As a result of this distortion, a significant amount of light falls outside the active area of the DMD. This overfill light is lost and does not contribute to image or screen brightness.